In Senate and House races in states from Arizona to North Carolina, Democrats have used TV ads and mailers to either denigrate establishment GOP candidates or promote their more conservative primary opponents. The goal is to get the more conservative — and, in theory, less electable — GOP pol to the general election.

The tactic, which has aided Democrats in the past, hasn’t yielded much success so far this year. But the party has at least three opportunities on Tuesday — in congressional primaries in California and New Jersey. In a season when Democrats are mostly playing defense, strategists say it’s worth trying to meddle with a Republican Party riven by internal conflicts.

“In every cycle, we all look back and say, ‘Gee, that race sure would have been more winnable if only X candidate had won the primary.’ And this cycle, even more than in the past, the Democrats are committed to making sure that ‘what if’ turns into the inevitable,” said Jefrey Pollock, a Democratic pollster who is involved in a number of races this year.

The offensives in California and New Jersey have come in the form of sneak attacks launched quietly by Democratic groups in the final days before voters head to the polls.